This study is designed to evaluate the safety and efficacy of a regimen containing Cobicistat (COBI)-boosted atazanavir (ATV/co) plus emtricitabine (FTC)/tenofovir disoproxil fumarate (TDF) versus ritonavir (RTV)-boosted atazanavir (ATV/r) plus FTC/TDF in HIV-1-infected, antiretroviral treatment-naive adults. Development of COBI as a "pharmacoenhancer" could provide a beneficial alternative to RTV for use in combination with protease inhibitors.

Males and females of childbearing potential must agree to utilize highly effective contraception methods from screening throughout the duration of study treatment and for 30 day s following the last dose of study drug.

Age ≥ 18 years

Life expectancy ≥ 1 year

Exclusion Criteria:

A new AIDS defining condition diagnosed within the 30 days prior to screening